화학공학소재연구정보센터
Bioresource Technology, Vol.99, No.18, 8955-8960, 2008
Methods to improve the composting process of the solid fraction of dairy cattle slurry
Cattle slurry solid fraction (SF) with different dry matter (DM) contents was collected from two dairy farms and composted in static and turned piles, with different sizes and cover types, to investigate the effects of pile conditions on the physical and chemical changes in SF during composting and to identify approaches to improve final compost quality. Thermophilic temperatures were attained soon after separation of SF, but the temperature of piles covered with polyethylene did not increase above 60 degrees C. The rate of organic matter (OM) mineralisation increased for turned piles in comparison to static piles, but the maximum amount of mineralisable OM (630-675 g kg(-1)) was similar for all pile treatments. The C/N ratio declined from over 36 to a value of 14 towards the end of composting, indicating an advanced degree of OM stabilisation. Mature compost was obtained from raw SF feedstock as indicated by the low compost temperature, low C/N ratio, and low content of NH4+ combined with increased concentrations of NO3-. The efficiency of the composting process was improved and NH3-N losses were minimized by increasing DM content of the SF, reducing the frequency of pile turning and managing compost piles without an impermeable cover. (C) 2008 Elsevier Ltd. All rights reserved.